A wide variety of memory devices can be used to maintain and store data and instructions for various computers and similar systems. In particular, FLASH memory is a type of electronic memory media that can be rewritten and that can retain content without consumption of power. Unlike dynamic random access memory (DRAM) devices and static random memory (SRAM) devices in which a single byte can be altered, FLASH memory devices are typically erased in fixed multi-bit blocks or sectors. FLASH memory technology can include NOR FLASH memory and/or NAND FLASH memory, for example. FLASH memory devices typically are less expensive and denser as compared to many other memory devices, meaning that FLASH memory devices can store more data per unit area.
FLASH memory has become popular, at least in part, because it combines the advantages of the high density and low cost of erasable programmable read-only memory (EPROM) with the electrical erasability of EEPROM. FLASH memory is nonvolatile; it can be rewritten and can hold its content without power. It can be used in many portable electronic products, such as cell phones, portable computers, voice recorders, thumbnail drives and the like, as well as in many larger electronic systems, such as cars, planes, industrial control systems, etc. The fact that FLASH memory can be rewritten, as well as its retention of data without a power source, small size, and light weight, have all combined to make FLASH memory devices useful and popular means for transporting and maintaining data.
FLASH memory arrays can be employed with a variety of interfaces or bus designs. For instance, a serial FLASH memory is becoming increasingly popular due to an efficient signal interface and cost effective packages. For example, a serial peripheral interface (SPI) has gained industry acceptance due to a low pin count and high clock rates. SPI FLASH memory is utilized by chipset vendors requiring reduced pin-counts and customers demanding lower cost solutions. For instance, SPI can provide a lowest pin-count solid state FLASH memory solution which equates to smaller board area and minimal signals to route. As system-on-a-chip (SoC) integrate more and more features, a low-pin count and low cost memory solution is attractive.